Rotary eraser.



W. R. GARDNR.

ROTARY ERASYER. APPLICATION FILED 00T.5, 1908.

Patented Sept. 7, 1909.

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:errants PATENT onirica.

Ywnmntiam R. l GARDNER? or Los ANGELES, oALr-roRmA.'

.ROTARY simsen.

To dll whomit may concern: f I

Be it known that I, `W1LLIM R. GARDNER,

a citizen ofthe United States, vresiding at "Los ngeles, in the countyof Los Angeles and State of California, have invented a new and usefulRotary Eraser, of which they lfollowing' is a specification.

This invention relates to orotary erasers, and the object of theinvention is to produce .a rotary movement of the eraser whereby theoperation of erasing maybe performed -more expeditiously thanheretofore.

A further object is to restrict the erasing operation'of the -exact areato be erased, thereby making it possible to erase a single letter of aword without erasing other let-y ters of the word, and to increase theerasing `qualities of the eraser.

A further object. is to provide a stable or nonslipping support'forContactin with the the area to e erased,

the process of erasing, the support preventing the instrument from siftinoi which otherwisemight occur owing to the rapid rotation andpressure of the eraseragainst the paper.

The accompanying drawings illustrate the invention, and referringthereto Figure 1.'

is a side elevation of the device. liig. 2 is a longitudinal sectionthrough the device. Fig. 3 is a cross section on line ac3-ap, Fi 2. Fi 4is across section on line actm4, Fig. .2.

he device comprises an outer barrel v1 and an inner barrel 2 which isslidable in theouterbarrel, thedower portion of the barrel .2 beinglslightly reduced in diameter, 'as

shown Yin Fig. 2, to avoid friction when the two-'barrels are.telescoped The lower end of the inner :barrel-12l 1s -formed with vfoursegmental Afeet 3, the edges of which are Iadapted to be pressed againstthe paper surrounding thearea to-be erased and form a 45 nonslippingsupport for the instrument dur'- ing the process of. erasing.

Screwedto the upper end of the barrel 1 isa cap v-4 to which isy secureda fork 5, the

'tines 6 of which extend down through the main barrel y1 and through twonotches 7 formed in the head 8 ofthe barrel 2, the head 8 having acentral .perforation with which the notches 7 communicate. A shaft 9 isarranged with its upper end rotatably mounted in the perforated head 8,while the lower end of shaft 9 is grooved at 10 andv .rpeoiotion d!ALetters "Patent,

Applioationled october 5,1908. Serial No.,456,349.

flvatentell Sept. 7,1909.

' journaled in a plate l1 slidable within the ,barrel 2. A chuck oreraser holder 12 is carried on the lower end of the shaft 9, and

the eraser 13 is supported by the holder 12.

flhe shaft 9 has a spiral roove 14 which is engaged by two inward ypro'ectinfr lugs 15 formed on the lower ends o the fork 5. A coil comression spring 16 is located in the barrel 1 between t e cap 4r and head8, while a-coil tension sprin 17 is located in the barrel 2, the upperen of spring 17 being secured to the iead 8 andthe lower end beingsecured to the plate 11. It will be oliserved that the tendency of thesprin 17 is to withdraw or lift the shaft 9. ig. 2 shows the minimumcontraction of sprin 1.17, the shaft 9 and eraser 13 being retracte tothe farthest point they occupy normally,

at which time the eraser 13 lies housed withinthe lower end of thebarrel 2.

In operation the legs 3 of the instrument are placedover the space to beerased, then by pressing down the barrel 1 the lugs 15of thefork 5 ridedown the spirally ooved shaft 9 and thus cause the shaft an eraser torotate. lThis downward movement of lugs 15 in the groove 14 exerts a'downward.

pressure on the shaft 9 in addition to the rotary pressure thereon., andthis downward pressure is suiliclent to overcome the spring 17 and forcethe shaft 14 downward until the eraser 13 makes contact with the paperand the rotation of the eraser performs the The s ring 17 prevents theeraser 13 from being orced a ainst the paper with too great a pressurean thus obviates tearing of the paper or undue abrasion thereof. One ofthe most important reasons foi' the employment of the spring 17 is this:The 1e s 3, in order to prevent the barrel 2 from `s ipping, must remainin contact with the paper during the erasing operation, and this contactis secured by the downward pressure of the upper spring 16 which iscompressed when the barrel l is moved down. It is obvious that while thelegs 3 are thus stationary on the paper it becomes necessary fortheeraser 13 to be capable of a longitudinal movement, even though slight,with respect to the surface of the a er, because the eraser isconstructed usua ly of yielding material and it will necessarily bepressed fagainstthe paper with varying degrees of pressure. Thus toprovideifor this move- -ment of the eraser, the shaft 9 is permitted alongitudinal movement within the barrel 2 A J Q from the "oint shown 1nFig. 2 to a point at which't e tip of the eraser 1s substantially flushwith the ends of the legs 3, and to retract the eraser and shaft 9 thespring 17 is employed. Thus durlng the downward movement of barrel 1sprin 16 is contracted,

and spring 17 is ex ande as the plate 11 slides down in barre 2, and assoon as pressure of the linger is removed from barrel 1, the spring 16forces the barrel 1 upward and at the same time spring 17 pulls up theshaft 9, bringing the parts into lnormal. position shown in Fig. 2.

What I claim is 1. An outer barrel, an inner barrel slidable therein, aVspirally grooved shaft with' its upper end rotatably a'nd slidablymounted in the end of the innerf barrel, a. plate slidable in the innerbarrel in which plate thelower end of the shaft is ]ournaled, 'a

holder for van eraser on the lower end of said lshaft, a fork connectedat its upper end to the outer barrel and extendin through the head ofthe inner barrel,'sai Afork havin lugs which engage the spirally grooveshaft, a coil vcompression spring in the. outer barrel, and a coiltension springwithin the inner barrel, one end of the latter springbeing* attached to thehead of the inner barrel and the other endattached to said slidable plate. Y'

2. An outer barrel, an inner barrel slidable therein, aspirally-'grooved shaft with its upper end rotatably and slidably mounted in the end ofthe .inner barrel, a plate slidable in the inner barrelin'which plate the lower end of the'shaft is journaled, a holder for aneraseron the lower end of said shaft, a fork connected at its upper end,to the' outer barrel and extendm through the head of the inner barrel,said fork having `lugs which engage` the spirally 'grooved shaft, a.coil compresslon spring 1n the outer barrel, and a coil tension s ringwithin the inner barrel, one end of the atter spring being attached tothe head of the'in- `ner barrel and the other end attached to saidslida'bley plate, the lower end of the inner barrel projecting/below theeraserv holder.

' '3.- A pair of telescopic barrels, a spirally grooved shaft rotatablymounted in one bark,rel and having a limited lon itudinal move-l menttherein, means carrie b the other barrel for engaging the spira lygrooved shaft to impart rotation thereto when the barrels aretelescoped, a holder carried on vthe lower end of said shaft, a coilcompression s ring for extendin said'barrels, and

a coi tension s ring or vretracting said shaft and control ingltslongitudinal move- 1 fment.`-

4Q'A'pair `of' telescopic barrels, a ca .screwed Ito the outer barrel, afork secure to the cap, the head of the inner barrel being perforatedand having two notches at the perforation through which the tlnes ofsald fork project, a spirally grooved shaft extending through theperforated head of the inner barrel and engaged by the tines of saidfork for the rotation of the shaft, a

slidable plate in the inner barrel in which the lower end of the shaftis rotatablyI mounted, an eraser holder on the lower end extendingthrough the perforated head of vthe inner barrel and engaged by thetines of said fork, for the rotation of the shaft, a slidable plateinthe inner barrel in whlch the lower end of the shaft is rotatablymounted, a compression spring between said cap and the head of the innerbarrel, a tension spring connected at one end to said plate and at theother end to the head of the 4to the lower end of said shaft below saidlate, said inner tube having feet which pro- ]ect below said holder. 6;-A rotary eraser 'comprising a pair of telescopic members, the lower endof the -lower memberjbeing adapted to be pressed against the pa er andforming 'a non-sli pmg support orthe instrument, a spiral y groovedlshaft .within said members mounted to rotate and. capable oflongitudinal movement `therein, an eraser carried on. the lower end ofsaid shaft, and means engagin the grooved shaft and operating by the teescopical movement of the two members to operate the eraser.

` 7. A rotary eraser comprising a tube, the lower end of which isadapted to be ressed against the fpa er and forma non-s ipping supportfor t e instrument, a splrally groovedg'shaft within said tubev mountedto rotate and capable of lon 'tudinal move- .ment therein, an eraser ont e lower end of said shaftyand means slidable relativel vto said tube'and engaging the grooveds aft foroperating the same;

In testimony whereof, I have hereunto set mty hand at Los Angeles, Cal.,this 21st day o September 1908.

- WILLIAM R. GARDNER.

cIn presence 01?--v vl G. T. HACKLEY,

- FRNK L. A. GRAHAM;

linner barrel, and an eraser holder secured

